Intracholecystic Papillary Neoplasm of Gallbladder: Clinicopathological Spectrum from Low-grade to High-grade Dysplasia – A Four Case Series

Intracholecystic papillary neoplasm (ICPN) is an uncommon preinvasive epithelial tumour of the gallbladder with variable malignant potential. This retrospective study evaluated the clinicopathological spectrum of four ICPN cases diagnosed on cholecystectomy specimens. Clinical, gross and histopathological features including epithelial subtype, grade of dysplasia and stromal invasion were analysed. Patients ranged from 32 to 68 years and lesion size varied from 0.8 to 9 cm. Gastric, biliary and mixed phenotypes were identified. Two cases showed low-grade dysplasia and two showed high-grade dysplasia. No stromal invasion was identified. In this limited series, larger lesions and biliary/mixed differentiation appeared to correlate with higher grades of dysplasia. ICPN represents a morphologically diverse preinvasive lesion with a spectrum of dysplasia, and accurate recognition is important because of its malignant potential.